Friday, March 31, 2017

How to adjust seating to the proper position while driving

Many drivers do not position themselves correctly in their cars and therefore seriously lack control and comfort while driving. A good driving position can actually help preventing accidents, improve safety should an accident occur, and improve driving comfort. To adjust to the proper seating position, use the following tips.

Steps

1. Wear proper clothing. Driving should be done with clothing that doesn’t limit the driver. In the winter, coats can interfere with proper steering as well as with proper adjustment of the seat and the operation of seat belts. Choose light and comfortable clothes.

Footwear is obligatory. The shoes have to be placed snugly on the feet (unlike slippers) and fit nicely on the pedals (unlike boots, muddy soles, or high heels). A shoe with a thin but slightly dense sole is ideal.

The driver is also advised to wear a set of pants that run all the way down to the knee, even if it means wearing a set of pants over shorts or a swim-suit.

2. Position yourself correctly in the seat itself. Make sure you sit straight and that your buttocks and back are square and completely squeezed into the seat. This helps to avoid backaches, possible back injuries and maintains awareness during long drives.

3. Adjust the seat distance. The seat should always be positioned with regard to the pedals. Press the brake pedal fully with your right foot and fully depress the clutch (in a manual transmission car) or dead pedal (in an automatic). The distance should be adjusted so that with fully depressed pedals, your knees remain slightly bent (about 120 degrees).

To make sure your check is accurate, start the engine and press on the brakes a few times before performing the check to build up pressure.

If the knee straightens, you are too far back. If it's bent close to 90 degrees, it's too close.

A fully extended leg results in the knee locking-up. This reduces the leverage and feel of the pedals, increases effort, and puts you in risk of severe injuries to the feet in a collision;the straight knee will be fractured whereas the bent knee would fold down. Furthermore, the bone would project the shock up to the pelvic and lower spine.

A knee excessively bent (when the driver sits too close) at an angle of about 100 degrees, does not support the body effectively and results in bad blood circulation. It can also hit the under-dash in a collision.

The thighs should be placed as far apart as is comfortable. In small cars, most people can create a wide enough base as to lean their knees against the center console on one side and the door on the other.

The feet should be placed with the heels on the floor and the balls of the feet pressing against the pedals. The right foot in particular should be able to pivot between the throttle and brake pedal while the heel is placed roughly in front of the brakes. This might mean that you don't cover the brake pedal fully when pressing it and that pressing the throttle is done with the foot at an angle, contacting the pedal close to its lower edge. This is the correct way to utilize the feet.

The left foot should be resting over the dead-pedal whenever not working on the clutch (or, in an automatic, at all times). This increases support to the pelvis and allows the driver to brace the body by applying pressure against the footrest in corners or in events of strong braking instead of hanging onto the pedals or steering.

4. Adjust the rake of the seat. This should be as parallel as possible to the steering. It is impossible to reach a perfect adjustment (and it's also not really necessary), but by adjusting the rake of the seat to an upright angle of about 110-95 degrees, we can reach a suitable adjustment.

We cannot reach a perfect adjustment because placing the seat too upright will put pressure on the lower vertebrae, place our head too high, and because the steering itself is placed in an angle. We can adjust the seat back to a relatively upright position and then use the adjustment of the steering itself to place it as parallel to the back as possible.

After adjusting the seat, including the height and the adjustments to the steering itself (below), we check the adjustment in the following manner: We place the wrist of our hand just over the topmost portion of the wheel. We should be able to place the wrist flat over the wheel and even bend it somewhat over the rim, while still keeping the shoulders (shoulder-blades) against the seat's back. This should be done with the arm straight but without putting in excessive effort.

If our wrist only touches the face of the wheel (rather than be placed flat over it), or it we can only put the heel of the palm on the wheel, or if we need to lean our scapulae (shoulder-blades) forward -- we are too far back. This will make us lean forward somewhat when we steer.

If we can touch the top of the wheel with our forearm or touch the top of the wheel with the wrist with the hand bent, we are too close to the wheel.

In vehicles with large, horizontal steering rims (mainly trucks), we cannot reach such a posture and we just need to check that we can grip the topmost portion of the wheel without locking the elbow fully and without bouncing the scapulae forward.

5. Adjust the steering height. Where adjustable, the steering height should be adjusted to as parallel to back angle, and to a clear view of the dashboard through the rim. The ideal adjustment should also allow us to grip the wheel properly (at 9 and 3, see below), with our palms just lower than our shoulders.

6. Adjust the steering distance. Where adjustable, this should be adjusted with the steering wheel height, to as parallel to the back as possible. While gripping the wheel properly, our elbows should be bent at about 120 degrees. There should be a minimal clearance of 10" (and preferably 30cm) between the center of the steering hub and the base of the breastbone (sternum). It should also not be further away that 45 centimeter (17.7 in).

7. Adjust the seat height. This should allow us to see forward clearly, while still having a clear view of the dashboard, and proper height relative to the wheel and pedals. In most cars, the proper height for forward vision should allow us to place five fingers (a hand width) between our head and the ceiling.

In cars with open or high ceiling, adjust so that you eyes are placed just above the center of the glass, without the visor obstructing your forward vision when open.

After readjusting the height, recheck the feet to make sure the height adjust had not compromised it.

8. Adjust the head restraints. Place the headrest to a height just above your eyelids, and (more importantly) -- as close to the head as possible (2-3cm). A head-restraint further than 7 centimeter (2.8 in) increases the risk of whiplash. Keep in mind that while driving our head bends forward a bit more. If you cannot adjust the head-restraint to the proper distance, you need to compensate by increasing the backrest tilt.

9. Make additional adjustments as necessary.

Lumbar support: Should provide equal pressure across the whole length of the back. For drivers with lumbar problems without such an adjustment, you can use one or two rolled towels.

Side Bolsters: Should be adjusted for the maximum possible hip support without limiting the ability to depress all pedals fully.

Seat base reclining: Should keep the thigh in full contact with the seat. Avoid too much reclining which will create pressure behind your knees, or interfere with strong braking (you should not apply pressure against the seat).

Pedal adjustments: Should allow operation of the pedals as described above as comfortably as possible. You should be able to place your heel roughly in front of the brakes, place your foot on the brakes with the slightest possible offset to the right, and pivot as easily as possible towards the throttle pedal on the right, while keeping your knee bent at about 100 degrees.

10. Position your hands properly. Your hands should both be on the wheel, at the 9 and 3 position. This increases the leverage on the wheel to a maximum. Your palms should be placed against the outer diameter of the wheel and the thumbs should be lightly hooked on the cross-brace of the wheel.

Grip and stabilize the wheel not only with the thumbs and/or palms, but mainly with your fingers and fingertips. In general, keep the grip of the wheel as light as possible without losing your control over the wheel. This results in better control and less fatigue.

Keep both hands on the wheel. Steering with one hand makes the weight of the hand work on the wheel, for which the shoulder muscles must be used to keep the wheel steady, resulting in a twist of the spine, especially if you get into the (bad) habit of holding the wheel from its top.

11. Wear your seat belt properly. Adjust the lap-belt as snugly as possible over the waist. The belt should be physically tightened and placed as low as possible, on the pelvic bones, rather than the soft belly.

The shoulder strap should be adjusted to the height, so that the mounting is higher than the shoulder, and that the strap itself is placed over the acromion (middle of the shoulder), which is felt as a socket midway between the arm and neck.

If the shoulder strap is placed on the neck or even on the collar bone (clavicle), it is too high and will cause fractures to the clavicle and cuts the neck.

If the strap is placed too low on the shoulder itself or on the arm/under the armpit, it will not support the body and cause severe cuts to the arm.

All passengers should be strapped, and little children need to be harnessed in the suitable child seats and boosters. There are also special straps for pets. There are also other points that are worthwhile for the passengers:

Head restraint adjustment

Window adjustment

Proper placing of limbs relative to airbags: Avoid placing feet over the passenger's airbag or placing hands in the way of the lateral or curtain airbags, etc...

Proper distance from the dashboard

Full and erected seating: Full contact of the back and the seat, and an erected rake angle for the front passenger, to avoid "submarining under the lap belt.

Awareness: Falling asleep is dangerous for passengers. The front passenger should be awake to monitor and assist the driver, and to avoid acute abdominal injuries in a collision, which are intensified when the person is asleep.

Not all seats of the car are equally safe. The middle-rear seat is considered safest, followed by the seat behind front passenger seat, then the seat behind the driver, the front passenger seat and the driver being in the greatest threat. This division changes in cars with additional seats (minivans) or when the middle-back lacks a diagonal or adjustable belt or a head-restraint.

12. Check your visibility. With this position, your eyes will be placed in front of the center or upper half of the glass for improved visibility. Keep your eyes relaxed rather than trying and focus, and keep the eyes up rather than down. You will see more and further away, while still being aware of your surrounding with your peripheral vision.

Adjust your mirrors to give you a broad field of vision to the rear and sides (see in links below) at the glance of an eye or a slight tilt of the head (if you have a narrow field of vision due to illness or age). In some cars, you might also need to be ready to lean slightly forward or take a slight peek to the side ("Shoulder check") to make sure you see everything around while driving.

13. Keep objects in the car low, on the floor, preferably at the front seat. Do not keep anything around the driver's seat, because it might slip under the pedals.

In general, anything not stock is not wanted: A convex mirror mounted on the center mirror, a padded cover of the steering wheel, things dangling about on your rear-view mirror -- these are all bad things that can also prove hazardous in an accident.

Windows, in this respect, are best either completely closed, slightly opened or almost fully opened, rather than half-way down, in which case the head of the driver or one of the passengers might hit it. Always keep one of your front windows slightly opened for fresh air.

Open windows on highways can create drag that impairs fuel consumption and even the stability of the car, so it's best to only keep one or two windows slightly opened at most.

On rugged terrain, the windows should be fully closed or fully opened to avoid rocking the window's bushings.

While it is possible to fit a quality, vacuum-adhesive interior mirror to view the back seat, in long drives with the whole family, it's best for the front passenger to be the one in charge of the inside of the car, and for the driver to focus himself on the road. Do not adjust your stock interior mirror to see the back seat and do not use wide-angle convex mirrors as well.

Likewise, avoid placing a child in the front seat, regardless of child restraints or airbags.

15. Use the air-conditioning to demist fumes on the windshields, and to provide a comfortable environment. It's better to use the car heat in the winter instead of driving with heavy clothing that interferes with steering and with the function of the seat belt. Keep one window slightly open for fresh air both in the summer (for oxygen) and winter (for fresh cold air).

The air conditioning is there to be used -- open the A/C periodically, even in the winter, and open the heating periodically -- even in the summer -- to ensure proper mechanical function of the two over time.

A/C air recirculation is very efficient because is blows large amounts of air. However, you need some fresh air through the driver's window. Likewise, if the windscreen is very heavily misted, opening the A/C for fresh air (along with an open window) can do better. Using external circulation is also efficient when you try to cool down a very hot cabin before entering it.

The A/C can also clear out bad smells. A few minutes before you turn off the car, close the air conditioner and air circulation, but keep the fan blowing air. This will channel out waste in the air ducts via a little hose inside it. Likewise, in a hot summer day, it's worthwhile to keep the heating blowing full time with all windows and doors open, to refresh the cabin.

The heating is also a good choice for when the engine starts to overheat. In highways, stopping on the hard-shoulder is so perilous that it is better to keep on driving towards a safe stopping place, even in the price of causing damage to the car (like overheating the engine). Using the heating to disperse engine heat can help reaching a safe stopping place without the engine reaching critical levels of heat.